Question

select all that apply
which of these is true about the development of antibiotic resistance in bacteria?
the presence of antibiotic selects for resistant bacteria.
a resistance gene provides a reproductive advantage to resistant bacteria in the presence of antibiotics.
resistant bacteria are present in a population due to random mutation.
even without the presence of antibiotic, the resistance mutation provides an advantage.
there are generally equal numbers of resistant and susceptible individuals in a typical population of bacteria.

Explanation:

• The presence of antibiotic selects for resistant bacteria: Antibiotics act as a selective pressure. Non - resistant bacteria are killed, while resistant ones survive and reproduce.
• A resistance gene provides a reproductive advantage to resistant bacteria in the presence of antibiotics: Resistant bacteria can survive and multiply when antibiotics are present, giving them a reproductive edge over non - resistant bacteria.
• Resistant bacteria are present in a population due to random mutation: Mutations are random events. Some of these mutations can confer antibiotic resistance.

• Even without the presence of antibiotic, the resistance mutation provides an advantage: In the absence of antibiotics, resistance mutations may not provide an advantage. In fact, they may sometimes be a burden (e.g., require extra energy for resistance mechanisms).
• There are generally equal numbers of resistant and susceptible individuals in a typical population of bacteria: In a non - antibiotic environment, the number of resistant bacteria is usually much lower than susceptible bacteria as there is no selective pressure for resistance.

Answer:

• The presence of antibiotic selects for resistant bacteria.
• A resistance gene provides a reproductive advantage to resistant bacteria in the presence of antibiotics.
• Resistant bacteria are present in a population due to random mutation.